By combining more precise core-shell nanoparticle synthesis techniques with electronic structure theory to predict the properties of nanoparticles, nanotechnology researchers have produced a better catalyst for fuel cells. From “‘Designer’ catalyst fights fuel cell poisoning“:

US scientists have designed from first principles nanoparticles that efficiently oxidise carbon monoxide (CO) — a contaminant commonly found in hydrogen used to run fuel cells.

A major problem facing fuel cells is that the hydrogen-rich materials feeding the reaction often contain CO, which is formed during hydrogen production. This CO ‘poisons’ the electrodes in the fuel-cell devices, deteriorating their efficiency.

Now, a team led by Bryan Eichhorn of the University of Maryland and Manos Mavrikakis of the University of Wisconsin, Madison, have designed and made a catalyst for the preferential oxidation (PROX) of CO comprising a ruthenium (Ru) core inside a Platinum (Pt) shell…

I am certainly beyond the limits of what I truly understand, but if you oxidize carbon monoxide, do you not end up with carbion dioxide? If so, will this not diminish the apparent desireability of the whole enterprise?

Yes, oxidizing carbon monoxide gives you carbon dioxide, but the issue here is that very small amounts of carbon monoxide can poison the catalysts, so the amount of carbon dioxide produced would also be very small compared to the amount of electricity the fuel cell produces from hydrogen.

Carbon dioxide is preferable to carbon monoxide as a pollutant. That really isn’t the issue. Carbon monoxide (and carbon dioxide, I think) can be a byproduct of hydrogen production, depending on the process. It’s a minor component of feedstock for fuel cells, but it can have a dramatic effect on their efficiency and lifetime. Hydrogen is best thought of like electricity – it’s not a primary energy source, it’s an energy transport mechanism. If these new fuel cells can run effectively on less pure hydrogen, it means that less energy has to be spent producing their fuel. So it’s better all around.